This invention relates generally to safe hypodermic syringes and more particularly to safe, reusable hypodermic syringes employing a hermetically sealed disposable cartridge containing both medication and a hollow hypodermic needle cannula which is exposable externally of said syringe only during the injection of the medication into a patient and which is then retractable completely back into the cartridge after the injection, with the cartridge and the needle contained therein being immediately disposable, with the entire process requiring the use of only one hand of the operator.
Hypodermic syringes of the type having a hollow needle cannula open at both ends and a pre-filled cartridge of fluid medication for injecting such medication from the cartridge to a targeted tissue area of a patient are well known in the art. However, before or after the injection, the needle is typically locked in an axially extended position projecting outwardly from a distal bore formed through the syringe cylinder.
In many cases, the needle is injected into a patient having a communicable disease such as AIDS or hepatitis. Prior to the disposing of the needle, or both the syringe and the needle, the hypodermic needle frequently must be removed from the syringe and broken or destroyed to prevent reuse. Dentists, doctors, nurses, and other health care workers are especially susceptible to accidental and potentially infectious needle strikes due to the careless handling or breaking of the needle and disposing of the needle after use.
The most life-threatening of the communicable diseases is AIDS. AIDS can be contracted by accidental puncture wound from a contaminated needle. This can occur by several methods:
1. Attempting to recap a contaminated needle. PA1 2. Disposal of a needle in a non-rigid container. PA1 3. Transfer of a syringe between health care personnel. PA1 1. A plastic capped needle is threaded onto a syringe. PA1 2. A glass cartridge (with medication) is loaded into the syringe or alternatively medication is drawn into a syringe from a multidose vial. PA1 3. The plastic cap is removed and the needle is exposed and inserted into the patient. PA1 4. The injection is given. PA1 5. The syringe (with the exposed contaminated needle) is passed to an assistant. PA1 6. The assistant disposes of the needle.
The current method of syringe preparation, injection and disposal is normally as follows:
Such accidental needle strikes typically require a blood test for such diseases as AIDS and hepatitis. The corresponding cost and inefficiency of testing medical workers who have received such an accidental needle strike can be considerable, which may be particularly damaging to a medical facility which is striving for economy. Should the patient be infected with the HIV virus then the person pricked with the needle contaminated by the infected patient has an extremely high risk of eventually dying from AIDS. Further, such accidental pricking could result in expensive personal liability to the facility in which the pricking occurred.